The present invention relates to a mounting system for vibration-damped (and oscillation-damped) support of a vehicle cab on a vehicle chassis.
Spring-loaded cab mountings serve to isolate and dampen oscillations and vibrations which originate from the roadway or other ground over which the vehicle travels, or from the drive train. The objectives of such damping are to improve the safety and comfort of the vehicle operator, and to avoid fatigue [(to the person or to materials)]. A number of spring-loaded cab mounting systems are known. E.g., elastic rubber dampers may be provided for absorbing external shocks. Essentially vertically oriented shock absorbers and coil springs are used to bolster comfort, with lateral stabilization provided by link rods disposed between the cab and the vehicle chassis (EP A 0,273,796).
In U.S. Pat. No. 6,273,203, an agricultural machine is described wherein shock-absorbing means (spring-loaded means) are disposed between the vehicle frame and the vehicle cab, which means comprise a plurality of vertically oriented hydraulic cylinders which are controllable in response to signals representing the angle of inclination, so as to tilt the cab relatively to the roadway, and to maintain the cab horizontal when the vehicle is traveling over hilly terrain. Elastic mounting elements are provided between the hydraulic cylinders and the vehicle cab, to dampen vibrations of medium and high frequency. The [(these)] elastic means are unsuitable to dampen horizontal oscillations.
DE A 27 08 477 discloses a spring-loaded system for the operator's cab of a truck or the like, which system supports the cab with respect to a vehicle frame. The cab is supported with respect to the frame by means of two pairs of lifting spring elements which engage the four corners of the cab, which springs are adjusted such that their lines of action mutually intersect pairwise in a transverse axis which extends at eye level of the occupants. In this way, the lifting spring elements mutually intersect [sic—i.e. their axes mutually intersect] pairwise in vertical longitudinal planes which pass through their articulation points. Of another configuration described in
DE A 27 08 477, the lifting spring elements are adjusted such that their lines of action all intersect at the center of gravity of the operator's cab. The lifting spring elements serve essentially to vertically support the cab. To provide support in the horizontal longitudinal direction of the vehicle, a total of four springs are employed which on one side are supported against the cab and on the other side are applied to two articulation points of coupling spring elements which are fixed to the vehicle frame. Similarly, four additional springs provide support in the horizontal transverse direction of the vehicle. Thus for support of the cab in all three directions, twelve springs are needed. This entails substantial fabrication cost. Elements for damping of the oscillation movements are not described in DE A 27 08 477.